Jonathan loved David. That's what the Bible says. They were soul-mates. The Bible does not call them "friends." It cannot be explicitly determined from the text that their love had — or didn't have — an erotic expression. The Hebrew has been heavily redacted, and the Greek and Latin amended by the excision and addition of suggestive or obfuscatory text. So while there is no explicit evidence of erotic fire there are clear signs of concerted efforts to clear the room of smoke.
All of this is irrefutable and objectivity true. Still, one of the more tiresome responses from the reasserter wing, in response to a statement such as that above, is that it somehow represents an eroticized Western culture's failing to understand the nature of friendship.* On the contrary, it is this unfounded assertion that represents a heterosexist or (at worst) homophobic culture's inability to recognize loving and devoted same-sex relationships, understanding them only in objective and erotic terms.
Even in frankly eroticized and libertine "gay cultures" gay men know the difference between their friends and lovers. Many gay men have deep, devoted, lasting friendships with other men in whom they have no erotic interest whatsoever. It is the heterosexist culture that doesn't want to ask and certainly doesn't want to be told about lifelong, monogamous, same-sex couples, — and so tries to conceal or erase or trivialize them by calling them "just good friends," or "roommates," or "war buddies who are sharing an apartment," or "bachelor girls" doing the same for purely monetary reasons. The "love that dare not speak its name" is bound and gagged by a culture that doesn't know love because it refuses to see it, and is afraid to acknowledge it.
This has been going on for over three thousand years, and it is about time to stop.
Tobias Stanislas Haller BSG
*An example, from the recent "traditionalist" paper written for the House of Bishops (page 11 in the draft version), in reference to any suggestion of a same-sex relationship between David and Jonathan.:
Here there is the obvious difficulty of arguing from an agenda rather than from explicit textual support. But it also exposes the weakness of modern western culture in not being able to foster or even understand deeply committed same-sex friendships that do not involve physical sexual expression.
Of course, this is precisely not a matter of an "agenda" (other than the heterosexist agenda to maximize Scriptural negativity towards same-sex relationships while minimizing anything positive); and the nature of the relationship as based on "love" rather than "friendship" is explicit in the text. If one were to change the names and recast the story with a man and woman, no one would argue it was about "very good friends." In fact, one need not engage in such speculation, since the same Hebrew verb for "love" of David is used in the same chapter (1 Samuel 18) in reference both to Saul's son Jonathan and his daughter Michal. David would later make it clear that the former was a more wonderful and greater love, in a text bowdlerized in the Vulgate.
Update 6/2/10: The thinking continues in part 2.